Radio channel aggregation and segmentation

Abstract

Multiple streams from multiple circuit paths are Block-TDM (Block-Time-Division-Multiplexing) aggregated into a single stream that passes via a single path through processing circuitry capable of handling the aggregated signal. The cost of providing redundant processing circuitry is avoided. After processing in the single path, the resulting signal is Block-TDM de-aggregated to generate multiple streams. Each output stream is substantially the same as if its corresponding input stream had been processed in a separate path using separate processing circuitry. The path-sharing technique is usable to pass multiple streams from multiple radio receivers through one superior Delta-Sigma ADC (DSADC) as opposed to using multiple flat ADCs to process information from the multiple receivers. In one example, the DSADC can be used because the aggregation is Block-TDM-based and the de-aggregator involves a digital low pass filter. In another example, the de-aggregator involves a decoder and the aggregator involves a precoder.

Description

BACKGROUND INFORMATION[0001]1. Technical Field[0002]The present disclosure relates to channel aggregation (i.e., path-sharing) and to channel segmentation (i.e., path-partitioning) in radio circuits.[0003]2. Background Information[0004]Many future radio systems will likely include radio transmitters and / or receivers that communicate using multiple antennas, and communicate with a given antenna over multiple frequency carriers, and that for a given frequency carrier and antenna combination involve separate In-phase (I) and Quadrature phase (Q) signal paths. A straightforward way to implement such a receiver is to provide a separate hardware signal path for each permutation of antenna, frequency carrier, and I / Q signal. For example, in one possible implementation of the LTE-A (Long Term Evolution—Advanced) wireless communication standard an 8×8 MIMO (Multiple-Input and Multiple-Output) transceiver uses eight antennas for receiving. The receiver of the transceiver may receive on any on...

AI Technical Summary

Benefits of technology

[0011]In a second aspect, due to the use of Block-TDM aggregating / de-aggregating and a suitably designed Digital Low Pass Filter (DLPF) in the de-aggregator, the ADC that processes the aggregated stream is a Delta-Sigma ADC (DSADC) that has desirable noise-shaping qualities and has superior performance as compared to flat ADCs used in conventional CDM-based path-sharing techniques. For still higher performance (less signal degradation of the signal due to aggregation and de-aggregation), an MMSE decoder is used in the de-aggregator rather than the DLPF. A precoder is also optionally used in the aggregator to transform the data in the aggregated stream prior to the data being supplied to the DSADC so that the data is less susceptible to the noise-generating characteristics of the DSADC. DSADC transfer function and noise performance is characterized and the results of the characterization are used to tailor the decoder and the precoder to optimize overall path-sharing performance depending on the characteristics of the particular DSADC used.

Problems solved by technology

Providing this much hardware would be costly and would result in a large amount of power consumption.

Because providing all this hardware is costly and consumes a large amount of power as described above, efforts may be made to use aggregation and de-aggregation techniques to share circuit paths.

The code-modulated scheme described, however, would have undesirably limited performance and / or would be undesirably large and costly to implement in future high performance MIMO LTE-A applications.

This approach, however, involves an undesirably large amount of circuit area and a large amount of power consumption.

Large-bandwidth ADCs in radio receivers such as the receivers of cellular telephone handsets are typically relatively large circuits that consume relatively large amounts of power.

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